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为了确定辽宁省坡耕地在不同耕作模式下土壤养分流失的特征,采用6°坡耕地,选取大豆作为种植作物,在天然降雨条件下,采用顺垄、横垄、免耕、免耕秸秆覆盖等耕作模式进行组合试验,观测分析降雨后氮、磷养分流失的变化特征,并通过回归分析方法说明了降雨对各土壤养分流失浓度的影响。结果表明:传统耕作顺垄+平翻模式下,氮、磷流失浓度最高,总氮为24.2mg.L-1,总磷为2.013mg.L-1;免耕和免耕秸秆覆盖在顺垄布置下与传统平翻耕作相比,分别减少总氮流失30%和32%,减少总磷流失18%和30%;与顺垄耕作组合模式相比,横垄耕作组合有效地减少径流中的各种养分流失浓度,减少总氮流失35%,减少总磷流失35.4%;硝态氮在横垄+平翻模式下流失量最低,为3.0mg.L-1,铵态氮在横垄+免耕秸秆覆盖模式下流失量最低,为6.8mg.L-1;径流中磷素浓度在0.1～0.6mg.L-1,水体富营养化现象严重;回归方程结果表明,天然降雨对径流中各养分的流失浓度影响显著。
In order to determine the characteristics of soil nutrient loss on sloping farmland in different tillage patterns in Liaoning Province, 6 ° sloping farmland was used to select soybean as planting crop. Under the condition of natural rainfall, the ridge, horizontal ridge, no-tillage and no-tillage straw mulching Tillage mode to test the changes of nutrient loss of nitrogen and phosphorus after rainfall. The effects of rainfall on the concentration of nutrients in soil were analyzed by regression analysis. The results showed that under the condition of conventional tillage with ridge and flat-bottom, the concentration of nitrogen and phosphorus was the highest, total nitrogen was 24.2mg.L-1 and total phosphorus was 2.013mg.L-1. No-tillage and no- Compared with the conventional flat tillage, the total nitrogen loss was reduced by 30% and 32%, and the total phosphorus loss by 18% and 30% respectively. Compared with the vertical and horizontal ridge tillage combination, Various nutrient loss concentrations reduced the total nitrogen loss by 35% and the total phosphorus loss by 35.4%. The nitrate nitrogen loss by the horizontal ridge-flattening model was the lowest (3.0mg.L-1) The lowest amount of soil loss under no-tillage straw mulching was 6.8mg.L-1. The phosphorus concentration in runoff was 0.1-0.6mg.L-1, and the water eutrophication was serious. The regression equation showed that the natural rainfall The nutrient loss concentration significantly affected.